This invention relates in general to fabricating fiber-reinforced membranes using elastomeric materials and, in particular, to a filament winding process suitable for fabricating flexible fiber-reinforced membranes for inflatable, deployable or expandable structures capable of sustaining high structural loads or providing thermal insulation to a structure. The invention relates especially to a filament winding process for fabricating a flexible membrane which may be inflated to provide a conically shaped deployable nose fairing for a missile.
Inflatable, deployable, or expandable structures have been manufactured in the past by calendering an elastomeric material onto fabric. Structures produced by this method have not been entirely satisfactory because of the splicing necessary for fabrication. This is especially the situation in cases where the inflated structure is subjected to high loads. Splicing is generally required between pieces of the calendered material to provide the desired shape. The requirement for splicing increases manufacturing time and costs and results in areas of structural weakness at the splice joint.
Filament winding has been used to form pressure vessels or open-ended elements such as pipes and conduits. For example, see U.S. Pat. No. 3,047,191. However, producing an inflatable or expandable structure such as a missile nose fairing by filament winding presents unique problems. The membrane must have a high strength-to-weight ratio to be suitable for use on aerospace vehicles. The yarns must be sufficiently impregnated with the elastomeric material so as to provide maximum shear and tensile capability. Similarly, gaps between yarns resulting from the winding process must be minimized in the final wound laminate. Forming the membrane in a conical shape also presents a special problem in minimizing the gaps between yarns because of the constantly changing diameter of the structure. Furthermore, there is a tendency for the windings to slip from position during the manufacturing process in the nose area where the surface has a steep slope.